Tuning Pt-skin to Ni-rich surface of Pt3Ni catalysts supported on porous carbon for enhanced oxygen reduction reaction and formic electro-oxidation

Abstract

Controlling surface composition of bimetallic catalysts is of significance in energy conversion and storage. Here, we controlled thermal treatment to synthesize different surface composition of bimetallic catalysts with average diameter <4nm. We report the synthesis of Pt3Ni catalyst with Pt-skin surface directly supported on porous graphitic carbon (PC), which showed over 300% increase in mass activity compared with Pt/C for the oxygen reduction reaction (ORR). The high activity and stability are attributed to the Pt-skin structure and the morphology of PC. When we tuned the surface composition to Ni-rich, it showed 300% increase in mass activity when compared with Pt/C towards oxidizing of HCOOH. Our approach to control surface composition can be used to design nanocatalysts for different reaction and are simple, effective and promotional to be industrialized.